1. Field of the Invention
The present invention relates to a safety brake system, and more particularly, to a safety brake system for garage doors.
2. Description of the Related Art
Conventional counter-weight spring systems used in garage doors have limited life. Therefore, when the spring breaks, the garage door falls down suddenly with potential damage to persons and/or objects in its path.
Many designs for safety mechanisms for garage door systems have been designed in the past. None of them, however, include a safety brake that stops the movement of a garage door when the mechanism for opening and closing breaks and drops suddenly. The present invention secures the door when the spring member breaks and permits a user to selectively bypass the safety brake in a controlled manner.
The typical weight of a garage door is between 200 and 400 pounds. There are some mechanisms relatively safe for opening and closing garage doors. However, they have parts (such as springs) with limited life. One of these mechanisms is described in U.S. Pat. No. 4,891,908 issued to Anthony G. Aquilina on Jan. 9, 1990 for a pneumatic door opener. Aquilina""s patented door operator system includes a counterbalancing assembly such as an axial torsion spring (114) mounted through a bar (115), which is secured above the door. A cable (116) is secured to the door and wound at on a drum (118). The cable (116) is axially driven by the torsion spring (114). Once the torsion spring (114) breaks, the door falls down suddenly. Cylinder 10 includes a pressurized fluid but it also requires a source 126 to operate. If spring (114) breaks, the pressurized fluid assembly will not act as a brake. In the present invention the pivot bolt is directly connected to the Aquilina""s bar (115). In the event that the spring loaded counterbalance mechanism fails the safety brake system of the present invention prevents the garage door from falling down.
Applicant believes that another related reference corresponds to U.S. Pat. No. 3,840,220 issued to McConnel et al. on Oct. 8, 1974 for a hydro-pneumatic counterbalance. McConnel""s patented device includes an inner cylinder having a counterbalance piston under hydraulic pressure and an outer concentric cylinder containing a highly pressurized gaseous fluid. An internal needle valve controls the communication between the two cylinders. The rate at which the piston moves is determined by the adjustment of the needle valve. However, it differs from the present invention because the McConnel""s patented invention is not a security device. It only controls the speed in the opening and closing traps and high weight garage doors. In fact, if the typical electrical motor mechanism is used it will have an extra load besides the weight of the door. This high cost device needs a high cost installation and maintenance, but it does not prevent the garage door from falling down when any of the six (6) instructions for installing the counterbalance unit on doors (Col. 5, lines 8 through 60) detailed in the patent is not met. The present invention is a security device that protects the doors from falling down when its mechanism fails and it is completely xe2x80x9cinvisiblexe2x80x9d until it is called to operate.
Another related reference corresponds to U.S. Pat. No. 4,417,418 issued to Warning in 1993 for an air powered door operation apparatus. Warning""s patent mentions braking and safety features such as an adjustable needle valve (Col. 3, lines 30 through 35). These features are only for limiting the amount of upward travel of the rod and the piston of the unpressurized cylinder. The present invention on the other hand, does not interfere with the opening/closing system of the door. It is incorporated to the rotational movement of the tension bar connected to the door without affecting its operation. Furthermore, in the present invention the flap valve provides a security device that stops the door when a sudden movement is detected.
Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.
It is one of the main objects of the present invention to provide a safety brake system that prevents a garage door from falling down when the opening and closing mechanism fails.
It is another object of this invention to provide a safety brake system that is volumetrically efficient and can be readily mounted to most existing garage doors systems.
It is yet another object of this invention to provide such a device that is inexpensive to manufacture and maintain while retaining its effectiveness.
Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.